Keeping Your Head On Target

• Authors: Aasef Shaikh, Emory University; Aaron L. Wong, Johns Hopkins University; David S. Zee, Johns Hopkins University; Hyder A Jinnah, Emory University
• Journal Title: Journal of Neuroscience
• Volume: Volume 33, Number 27
• Publisher: Society for Neuroscience | 2013-07-03, Pages 11281-11295
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1523/JNEUROSCI.3415-12.2013
• Subjects: Biology, Neuroscience; Health Sciences, Opthamology; Biology, Genetics
• Keywords: Science & Technology; Life Sciences & Biomedicine; Neurosciences; Neurosciences & Neurology; OCULAR MUSCLE PROPRIOCEPTION; IDIOPATHIC CERVICAL DYSTONIA; INTERSTITIAL NUCLEUS; SPASMODIC TORTICOLLIS; EYE-MOVEMENTS; POSTURAL RESPONSES; VISUAL LOCALIZATION; SUPERIOR COLLICULUS; REBOUND NYSTAGMUS; NEURAL INTEGRATOR

Abstract

The mechanisms by which the human brain controls eye movements are reasonably well understood, but those for the head less so. Here, we show that the mechanisms for keeping the head aimed at a stationary target follow strategies similar to those for holding the eyes steady on stationary targets. Specifically, we applied the neural integrator hypothesis that originally was developed for holding the eyes still in eccentric gaze positions to describe how the head is held still when turned toward an eccentric target. We found that normal humans make head movements consistent with the neural integrator hypothesis, except that additional sensory feedback is needed, from proprioceptors in the neck, to keep the head on target. We also show that the complicated patterns of head movements in patients with cervical dystonia can be predicted by deficits in a neural integrator for head motor control. These results support ideas originally developed from animal studies that suggest fundamental similarities between oculomotor and cephalomotor control, as well as a conceptual framework for cervical dystonia that departs considerably from current clinical views.